A quick rundown of the top 6 Java distributions: Oracle, OpenJDK, Adoptium, Zulu, Corretto, and Liberica
Java has never been dethroned as a mainstream programming language since it was introduced to the world. Even with languages like Groovy, Scala, and Kotlin trying to unseat it, Java is still a force to be reckoned with. For a language that has written so many programs for so long, there are a lot of Java distributions out there. Even big tech companies like Amazon and Microsoft have their own Java distributions.
Choosing the right Java distribution is primarily a matter of cost. Licensing is the main reason why distributions are created in the first place. And depending on the platform, it can also be a performance factor. So in this post, I'll outline some of the top Java distributions to help you make the right choice.
1. Oracle JDK
The steward of Java
The Oracle JDK is the official Java distribution from Oracle, the company responsible for the present and future of Java. In the English-speaking world, Oracle is referred to as The Steward of Java because Oracle acquired the rights to manage Java and the Java ecosystem when it acquired Sun Microsystems.
As the official distribution, the Oracle JDK is considered the most optimized of all Java distributions, especially for enterprise-class applications. It also comes with ongoing updates, security patches, and technical support. However, if you want to use it for commercial purposes, you'll have to pay for it.
Because Java is one of Oracle's signature products, a strong Java ecosystem is essential to Oracle's future. That's why Oracle is the largest supporter of OpenJDK. Oracle JDK is a distribution of OpenJDK that has been further optimized and enhanced with more convenient features.
2. OpenJDK
The foundation of all Java distributions
This is the leading community version open source distribution of Java. It is free to use for any purpose. Oracle acquired the Java platform and OpenJDK from Sun, IBM, MS, Red Hat and other tech giants support OpenJDK, and most importantly, it is maintained by a large number of developers around the world.
As I mentioned earlier, the OpenJDK is the foundation of almost every Java distribution, including the Oracle JDK. So you can trust it and use it. However, unless you're on the LTS version, you can't guarantee support, and it will always be below Oracle JDK performance-wise, which is something to consider when developing your service.
3. Adoptium (aka AdoptOpenJDK)
Easy to use OpenJDK
Adoptium was formerly known as AdoptOpenJDK. Adoptium is an open source distribution spearheaded by the Eclipse Foundation, once synonymous with open source IDEs, and supported by major technology companies such as IBM, MS, and Azul Systems.
Adoptium's goal is to make OpenJDK easy to use. As such, it supports a few things that OpenJDK doesn't, including
- Pre-built binaries: We provide pre-built binaries to save you the time of building OpenJDK on your own platform.
- LTS: Guaranteed updates, security patches, bug fixes, and more for a wider range of releases.
- JVMs such as Hotspot or Eclipse OpenJ9: Support for more types of JVMs, giving you more technology choices.
It's important to note, however, that they do not provide technical support for commercial use, which is something to keep in mind when using them in production.
4. Azul Zulu
Business distribution with technical support
Zulu from Azul Systems is another distribution built around OpenJDK. Zulu is also free to use for any purpose. If Adoptium is the distribution of choice for primarily, but not exclusively, open source development, Zulu is the distribution of choice for many enterprises. One reason is that it offers formal technical support for commercial use.
A big reason why enterprises choose the Oracle JDK over open source Java distributions is the fast and formal response to technical issues. Zulu has this as a strength. It also has strong optimizations and runs reliably on most platforms and operating systems.
On the downside, it's less community-driven than other distributions, so it may not be able to keep up with the needs of the Java community as quickly.
5. Amazon Corretto
Specialized for AWS infrastructure
Corretto is an OpenJDK-based open source distribution managed by Amazon. Amazon's infrastructure, including AWS, which handles the world's largest transactions, is said to be built on Corretto. As such, it's a distribution with a strong focus on performance and security, and it supports continuous delivery via LTS releases.
Corretto's features are both a strength and a weakness. It's optimized for use on AWS, which is its own service. If you are using AWS services, Corretto should be your first choice. If not, you may need to test its performance against other distributions.
Similarly, if you're using Azure as a cloud service, you might want to consider the Microsoft Build of OpenJDK™ (opens in a new tab) first, as it's optimized for that platform.
6. Consider the Liberica JDK
Distributions to consider for cloud-based Java services
Liberica JDK is a distribution from Bell Soft. It's the least known of the six distributions we're talking about today, but it's also one of the most popular with a certain audience.
For starters, Bell Soft focuses on cloud-based Java environments, touting fast deployment times and low memory and hardware requirements. It also has a number of related products, including Alphaquita Linux, which specializes in Java microservices.
Basically, it's free to use, open source, for-profit, and has official technical support, so I think it's worth including as one of your options.
7. 6 Distributions in a nutshell
The root of all Java distributions is the OpenJDK. And distributions have added various features on top of OpenJDK to make life easier for developers. Thanks to this, we can choose the best distribution for the characteristics of our service.
Depending on the distribution, it can be optimized for different platforms or highly specialized for a specific platform. They also differ in whether they offer technical support for commercial use. Last but not least, it's important to consider whether they keep the version of your service up to date.
7.1. Distribution Selection Criteria
Based on what we've seen in this post, if you're a large organization, you can start with the Oracle JDK once and for all, If you can afford it, consider Zulu, Corretto, MS, or Liberica, all of which offer technical support. For open source projects, I think Adoptium might be your first choice.
